Internal error with StackOverflowError while compiling a function

[rfourquet]

MWE:

julia> function swapliterals!(@nospecialize(swaps::AbstractDict))
           swaps === Base.ImmutableDict(Int128 => :big)
       end
swapliterals! (generic function with 1 method)

julia> swapliterals!(Dict(Int=>Int))
Internal error: encountered unexpected error during compilation of swapliterals!:
StackOverflowError()
jl_type_intersection_env_s at /local/src/julia/src/subtype.c:3305
emit_f_is at /local/src/julia/src/codegen.cpp:2553
emit_bits_compare at /local/src/julia/src/codegen.cpp:2503
operator() at /local/src/julia/src/codegen.cpp:2573
emit_guarded_test<emit_f_is(jl_codectx_t&, const jl_cgval_t&, const jl_cgval_t&, llvm::Value*, llvm::Value*)::<lambda()>&> at /local/src/julia/src/codegen.cpp:
2322
operator() at /local/src/julia/src/codegen.cpp:2354 [inlined]
[...]

[yuyichao]

Direct repro is code_llvm((a, b)->a === b, Tuple{Base.ImmutableDict{Int,Int},Base.ImmutableDict{Int,Int}}). So there needs to be a detection for loops when comparing immutables...